Monolithically framed pellicle membrane suitable for lithography in the fabrication of integrated circuits

Abstract

Monolithic framed pellicle membrane integrating a structural framing member with a membrane spanning the framing member. The monolithic frame pellicle membrane is suitable as an overlay of a reticle employed in lithography operations of integrated circuit manufacture. A semiconductor-on-insulator (SOI) wafer may be machined from the backside, for example with a bonnet polisher, to form a pellicle framing member by removing a portion of a base semiconductor substrate of the SOI wafer selectively to top semiconductor layer of the SOI wafer, which is retained as a pellicle membrane. In some exemplary embodiments suitable for extreme ultraviolet (EUV) lithography applications, at least the top semiconductor layer of the SOI wafer is a substantially monocrystalline silicon layer.

What is claimed is: 
     
       1. A monolithic lithography pellicle, comprising:
 a frame comprising substantially monocrystalline silicon; 
 a membrane comprising substantially monocrystalline silicon; and 
 an amorphous material between the frame and the membrane. 
 
     
     
       2. The pellicle of  claim 1 , wherein the amorphous material comprises predominantly silicon and oxygen. 
     
     
       3. The pellicle of  claim 2 , wherein the membrane comprises a minority impurity concentration. 
     
     
       4. The pellicle of  claim 3 , wherein at least one of the impurities in the membrane is boron. 
     
     
       5. The pellicle of  claim 1 , wherein the frame has a first crystal orientation; and
 the membrane has the first crystal orientation. 
 
     
     
       6. The pellicle of  claim 5 , wherein a front side of the membrane, opposite the frame, is a {111} crystal plane. 
     
     
       7. The pellicle of  claim 1 , wherein:
 the membrane has a thickness less than 200 nm; 
 the frame has a thickness of at least 3 mm; and 
 the frame encloses an interior area spanned by the membrane, and the interior area is at least 100 mm×100 mm. 
 
     
     
       8. The pellicle of  claim 1 , further comprising one or more thin film materials over a front side of the pellicle membrane, opposite the frame, wherein the thin film materials have higher emissivity than monocrystalline silicon. 
     
     
       9. The pellicle of  claim 1 , further comprising a layer of predominantly Ru in contact with the front side of the of the membrane, opposite the frame. 
     
     
       10. The pellicle of  claim 9 , wherein the Ru layer has a thickness less than 5 nm. 
     
     
       11. The pellicle of  claim 1 , further comprising a dielectric material layer comprising silicon and nitrogen on at least a portion of the frame. 
     
     
       12. The pellicle of  claim 11 , wherein the dielectric material layer is on a back side of the pellicle membrane, proximal to the frame. 
     
     
       13. A pelliclized reticle assembly, comprising:
 a lithography reticle including a feature pattern to be reflectively imaged upon a workpiece; and 
 a monolithic lithography pellicle, comprising:
 a frame comprising substantially monocrystalline silicon; 
 a membrane comprising substantially monocrystalline silicon; and 
 an amorphous material between the frame and the membrane. 
 
 
     
     
       14. The pelliclized reticle assembly of  claim 13 , further comprising an adhesive between a back side of the frame and the reticle. 
     
     
       15. The pelliclized reticle assembly of  claim 13 , wherein the frame comprises a first structural feature that interfaces with a complementary second structural feature on the reticle. 
     
     
       16. A method comprising:
 receiving a monolithic lithography pellicle comprising:
 a frame comprising substantially monocrystalline silicon; 
 a membrane comprising substantially monocrystalline silicon; and 
 an amorphous material between the frame and the membrane; 
 
 receiving a lithography reticle comprising a feature pattern to be imaged by a lithography system; and 
 mechanically coupling the frame with the reticle to contain the feature pattern within an interior cavity of the pellicle. 
 
     
     
       17. The method of  claim 16 , wherein mechanically coupling the frame with the reticle comprises curing an adhesive between a back side of the frame and a surface of the reticle. 
     
     
       18. The method of  claim 16 , further comprising depositing, upon the pellicle, a material layer comprising predominantly Ru over a front side of the pellicle membrane, opposite the frame, wherein the thin film materials have higher emissivity than monocrystalline silicon. 
     
     
       19. The method of  claim 16 , further comprising depositing, upon at least a portion of the frame, a dielectric material layer comprising silicon and nitrogen. 
     
     
       20. The method of  claim 16 , further comprising reflectively imaging the feature pattern upon a workpiece.